

<!DOCTYPE html>
<html lang="zh-CN" data-default-color-scheme=&#34;auto&#34;>



<head>
  <meta charset="UTF-8">
  <link rel="apple-touch-icon" sizes="76x76" href="/img/boshi.jpeg">
  <link rel="icon" type="image/png" href="/img/boshi.jpeg">
  <meta name="viewport"
        content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, shrink-to-fit=no">
  <meta http-equiv="x-ua-compatible" content="ie=edge">
  
  <meta name="theme-color" content="#2f4154">
  <meta name="description" content="">
  <meta name="author" content="wangpf">
  <meta name="keywords" content="">
  <title>Node介绍 - wpf的博客</title>

  <link  rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/4.4.1/css/bootstrap.min.css" />


  <link  rel="stylesheet" href="https://cdn.staticfile.org/github-markdown-css/4.0.0/github-markdown.min.css" />
  <link  rel="stylesheet" href="/lib/hint/hint.min.css" />

  
    
    <link  rel="stylesheet" href="https://cdn.staticfile.org/highlight.js/10.0.0/styles/foundation.min.css" />
  

  


<!-- 主题依赖的图标库，不要自行修改 -->

<link rel="stylesheet" href="//at.alicdn.com/t/font_1749284_6peoq002giu.css">



<link rel="stylesheet" href="//at.alicdn.com/t/font_1736178_pjno9b9zyxs.css">


<link  rel="stylesheet" href="/css/main.css" />

<!-- 自定义样式保持在最底部 -->


  <script  src="/js/utils.js" ></script>
  <script  src="/js/color-schema.js" ></script>
<meta name="generator" content="Hexo 5.1.1"></head>


<body>
  <header style="height: 70vh;">
    <nav id="navbar" class="navbar fixed-top  navbar-expand-lg navbar-dark scrolling-navbar">
  <div class="container">
    <a class="navbar-brand"
       href="/">&nbsp;<strong>Wangpf's blog</strong>&nbsp;</a>

    <button id="navbar-toggler-btn" class="navbar-toggler" type="button" data-toggle="collapse"
            data-target="#navbarSupportedContent"
            aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
      <div class="animated-icon"><span></span><span></span><span></span></div>
    </button>

    <!-- Collapsible content -->
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
      <ul class="navbar-nav ml-auto text-center">
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/">
                <i class="iconfont icon-home-fill"></i>
                首页
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/archives/">
                <i class="iconfont icon-archive-fill"></i>
                归档
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/categories/">
                <i class="iconfont icon-category-fill"></i>
                分类
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/tags/">
                <i class="iconfont icon-tags-fill"></i>
                标签
              </a>
            </li>
          
        
          
          
          
          
            <li class="nav-item">
              <a class="nav-link" href="/about/">
                <i class="iconfont icon-user-fill"></i>
                关于
              </a>
            </li>
          
        
        
          <li class="nav-item" id="search-btn">
            <a class="nav-link" data-toggle="modal" data-target="#modalSearch">&nbsp;<i
                class="iconfont icon-search"></i>&nbsp;</a>
          </li>
        
        
          <li class="nav-item" id="color-toggle-btn">
            <a class="nav-link" href="javascript:">&nbsp;<i
                class="iconfont icon-dark" id="color-toggle-icon"></i>&nbsp;</a>
          </li>
        
      </ul>
    </div>
  </div>
</nav>

    <div class="banner intro-2" id="background" parallax=true
         style="background: url('/img/article.jpg') no-repeat center center;
           background-size: cover;">
      <div class="full-bg-img">
        <div class="mask flex-center" style="background-color: rgba(0, 0, 0, 0.3)">
          <div class="container page-header text-center fade-in-up">
            <span class="h2" id="subtitle">
              
            </span>

            
              
  <div class="mt-3 post-meta">
    <i class="iconfont icon-date-fill" aria-hidden="true"></i>
    <time datetime="2020-08-04 21:12" pubdate>
      2020年8月4日 晚上
    </time>
  </div>


<div class="mt-1">
  
    
    <span class="post-meta mr-2">
      <i class="iconfont icon-chart"></i>
      724 字
    </span>
  

  
    
    <span class="post-meta mr-2">
      <i class="iconfont icon-clock-fill"></i>
      
      
      8
       分钟
    </span>
  

  
  
</div>

            
          </div>

          
        </div>
      </div>
    </div>
  </header>

  <main>
    
      

<div class="container-fluid">
  <div class="row">
    <div class="d-none d-lg-block col-lg-2"></div>
    <div class="col-lg-8 nopadding-md">
      <div class="container nopadding-md" id="board-ctn">
        <div class="py-5" id="board">
          <article class="post-content mx-auto" id="post">
            <!-- SEO header -->
            <h1 style="display: none">Node介绍</h1>
            
            <div class="markdown-body" id="post-body">
              <h1 id="Node-js-准备"><a href="#Node-js-准备" class="headerlink" title="Node.js 准备"></a>Node.js 准备</h1><h2 id="学前准备"><a href="#学前准备" class="headerlink" title="学前准备"></a>学前准备</h2><ul>
<li>Node.js 是什么<ul>
<li>JavaScript 运行时</li>
<li>既不是语言，也不是框架，它是一个平台</li>
</ul>
</li>
<li>Node.js 中的 JavaScript<ul>
<li>没有 BOM、DOM</li>
<li>EcmaScript 基本的 JavaScript 语言部分</li>
<li>在 Node 中为 JavaScript 提供了一些服务器级别的 API<ul>
<li>文件操作的能力</li>
<li>http 服务的能力</li>
</ul>
</li>
</ul>
</li>
</ul>
<h2 id="总结"><a href="#总结" class="headerlink" title="总结"></a>总结</h2><ul>
<li><p>Node 中的 JavaScript</p>
<ul>
<li>EcmaScript<ul>
<li>变量</li>
<li>方法</li>
<li>数据类型</li>
<li>内置对象</li>
<li>Array</li>
<li>Object</li>
<li>Date</li>
<li>Math</li>
</ul>
</li>
<li>模块系统<ul>
<li>在 Node 中没有全局作用域的概念</li>
<li>在 Node 中，只能通过 require 方法来加载执行多个 JavaScript 脚本文件</li>
<li>require 加载只能是执行其中的代码，文件与文件之间由于是模块作用域，所以不会有污染的问题<ul>
<li>模块完全是封闭的</li>
<li>外部无法访问内部</li>
<li>内部也无法访问外部</li>
</ul>
</li>
<li>模块作用域固然带来了一些好处，可以加载执行多个文件，可以完全避免变量命名冲突污染的问题</li>
<li>但是某些情况下，模块与模块是需要进行通信的</li>
<li>在每个模块中，都提供了一个对象：<code>exports</code></li>
<li>该对象默认是一个空对象</li>
<li>你要做的就是把需要被外部访问使用的成员手动的挂载到 <code>exports</code> 接口对象中</li>
<li>然后谁来 <code>require</code> 这个模块，谁就可以得到模块内部的 <code>exports</code> 接口对象</li>
<li>还有其它的一些规则，具体后面讲，以及如何在项目中去使用这种编程方式，会通过后面的案例来处理</li>
</ul>
</li>
<li>核心模块<ul>
<li>核心模块是由 Node 提供的一个个的具名的模块，它们都有自己特殊的名称标识，例如<ul>
<li>fs 文件操作模块</li>
<li>http 网络服务构建模块</li>
<li>os 操作系统信息模块</li>
<li>path 路径处理模块</li>
<li>。。。。</li>
</ul>
</li>
<li>所有核心模块在使用的时候都必须手动的先使用 <code>require</code> 方法来加载，然后才可以使用，例如：<ul>
<li><code>var fs = require(&#39;fs&#39;)</code></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
<li><p>http</p>
<ul>
<li>require</li>
<li>端口号<ul>
<li>ip 地址定位计算机</li>
<li>端口号定位具体的应用程序</li>
</ul>
</li>
<li>Content-Type<ul>
<li>服务器最好把每次响应的数据是什么内容类型都告诉客户端，而且要正确的告诉</li>
<li>不同的资源对应的 Content-Type 是不一样，具体参照：<a target="_blank" rel="noopener" href="http://tool.oschina.net/commons">http://tool.oschina.net/commons</a></li>
<li>对于文本类型的数据，最好都加上编码，目的是为了防止中文解析乱码问题</li>
</ul>
</li>
<li>通过网络发送文件<ul>
<li>发送的并不是文件，本质上来讲发送是文件的内容</li>
<li>当浏览器收到服务器响应内容之后，就会根据你的 Content-Type 进行对应的解析处理<div class="hljs"><pre><code class="hljs reasonml">res.set<span class="hljs-constructor">Header(&#x27;Content-Type&#x27;, &#x27;<span class="hljs-params">text</span><span class="hljs-operator">/</span><span class="hljs-params">plain</span>;<span class="hljs-params">charset</span>=<span class="hljs-params">utf</span>-8&#x27;)</span>;</code></pre></div>
</li>
</ul>
</li>
</ul>
</li>
<li><p>模块系统</p>
</li>
<li><p>Node 中的其它的核心模块</p>
</li>
<li><p>做一个小管理系统：</p>
<ul>
<li>CRUD</li>
</ul>
</li>
<li><p>Express Web 开发框架</p>
<ul>
<li><code>npm install express</code></li>
</ul>
</li>
</ul>

            </div>
            <hr>
            <div>
              <div class="post-metas mb-3">
                
                <div class="post-meta mr-3">
                  <i class="iconfont icon-category"></i>
                  
                  <a class="hover-with-bg" href="/categories/Nodejs/">Nodejs</a>
                  
                </div>
                
                
                <div class="post-meta">
                  <i class="iconfont icon-tags"></i>
                  
                  <a class="hover-with-bg" href="/tags/Node/">Node</a>
                  
                </div>
                
              </div>
              
              
              <div class="post-prevnext row">
                <article class="post-prev col-6">
                  
                  
                  <a href="/2020/08/05/08.%E5%9F%BA%E4%BA%8EExpress%20%E4%B8%8B%E7%9A%84%20%E5%A2%9E%E5%88%A0%E6%94%B9%E6%9F%A5%E9%A1%B9%E7%9B%AE/">
                    <i class="iconfont icon-arrowleft"></i>
                    <span class="hidden-mobile">基于Express 下的 增删改查项目</span>
                    <span class="visible-mobile">上一篇</span>
                  </a>
                  
                </article>
                <article class="post-next col-6">
                  
                  
                </article>
              </div>
              
            </div>

            
            <!-- Comments -->
            <article class="comments" id="comments">
              
              
  <div id="vcomments"></div>
  <script type="text/javascript">
    function loadValine() {
      addScript('https://cdn.staticfile.org/valine/1.4.14/Valine.min.js', function () {
        new Valine({
          el: "#vcomments",
          app_id: "hjxsDRXYScicliqD8I8JqoTu-gzGzoHsz",
          app_key: "qUcAEReEqeEVp5wwXJ41uCCp",
          placeholder: "说点什么",
          path: window.location.pathname,
          avatar: "retro",
          meta: ["nick","mail","link"],
          pageSize: "10",
          lang: "zh-CN",
          highlight: true,
          recordIP: false,
          serverURLs: "",
        });
      });
    }
    waitElementVisible('vcomments', loadValine);
  </script>
  <noscript>Please enable JavaScript to view the <a target="_blank" href="https://valine.js.org" rel="nofollow noopener noopener">comments
      powered by Valine.</a></noscript>


            </article>
            
          </article>
        </div>
      </div>
    </div>
    
    <div class="d-none d-lg-block col-lg-2 toc-container" id="toc-ctn">
      <div id="toc">
  <p class="toc-header"><i class="iconfont icon-list"></i>&nbsp;目录</p>
  <div id="tocbot"></div>
</div>

    </div>
    
  </div>
</div>

<!-- Custom -->


    
  </main>

  
    <a id="scroll-top-button" href="#" role="button">
      <i class="iconfont icon-arrowup" aria-hidden="true"></i>
    </a>
  

  
    <div class="modal fade" id="modalSearch" tabindex="-1" role="dialog" aria-labelledby="ModalLabel"
     aria-hidden="true">
  <div class="modal-dialog modal-dialog-scrollable modal-lg" role="document">
    <div class="modal-content">
      <div class="modal-header text-center">
        <h4 class="modal-title w-100 font-weight-bold">搜索</h4>
        <button type="button" id="local-search-close" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body mx-3">
        <div class="md-form mb-5">
          <input type="text" id="local-search-input" class="form-control validate">
          <label data-error="x" data-success="v"
                 for="local-search-input">关键词</label>
        </div>
        <div class="list-group" id="local-search-result"></div>
      </div>
    </div>
  </div>
</div>
  

  

  

  <footer class="mt-5">
  <div class="text-center py-3">
    <div>
      <a href="https://hexo.io" target="_blank" rel="nofollow noopener"><span>Hexo</span></a>
      <i class="iconfont icon-love"></i>
      <a href="https://github.com/fluid-dev/hexo-theme-fluid" target="_blank" rel="nofollow noopener">
        <span>Fluid</span></a>
    </div>
    
  <div class="statistics">
    
    

    
      
        <!-- 不蒜子统计PV -->
        <span id="busuanzi_container_site_pv" style="display: none">
            总访问量 
            <span id="busuanzi_value_site_pv"></span>
             次
          </span>
      
      
        <!-- 不蒜子统计UV -->
        <span id="busuanzi_container_site_uv" style="display: none">
            总访客数 
            <span id="busuanzi_value_site_uv"></span>
             人
          </span>
      
    
  </div>


    

    
  </div>
</footer>

<!-- SCRIPTS -->
<script  src="https://cdn.staticfile.org/jquery/3.4.1/jquery.min.js" ></script>
<script  src="https://cdn.staticfile.org/twitter-bootstrap/4.4.1/js/bootstrap.min.js" ></script>
<script  src="/js/debouncer.js" ></script>
<script  src="/js/main.js" ></script>

<!-- Plugins -->


  
    
      <script  src="/js/lazyload.js" ></script>
    
  



  <script defer src="https://cdn.staticfile.org/clipboard.js/2.0.6/clipboard.min.js" ></script>
  <script  src="/js/clipboard-use.js" ></script>



  <script defer src="https://busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js" ></script>





  <script  src="https://cdn.staticfile.org/tocbot/4.11.1/tocbot.min.js" ></script>
  <script>
    $(document).ready(function () {
      var boardCtn = $('#board-ctn');
      var boardTop = boardCtn.offset().top;

      tocbot.init({
        tocSelector: '#tocbot',
        contentSelector: '#post-body',
        headingSelector: 'h1,h2,h3,h4,h5,h6',
        linkClass: 'tocbot-link',
        activeLinkClass: 'tocbot-active-link',
        listClass: 'tocbot-list',
        isCollapsedClass: 'tocbot-is-collapsed',
        collapsibleClass: 'tocbot-is-collapsible',
        collapseDepth: 0,
        scrollSmooth: true,
        headingsOffset: -boardTop
      });
      if ($('.toc-list-item').length > 0) {
        $('#toc').css('visibility', 'visible');
      }
    });
  </script>



  <script  src="https://cdn.staticfile.org/typed.js/2.0.11/typed.min.js" ></script>
  <script>
    var typed = new Typed('#subtitle', {
      strings: [
        '  ',
        "Node介绍&nbsp;",
      ],
      cursorChar: "_",
      typeSpeed: 70,
      loop: false,
    });
    typed.stop();
    $(document).ready(function () {
      $(".typed-cursor").addClass("h2");
      typed.start();
    });
  </script>



  <script  src="https://cdn.staticfile.org/anchor-js/4.2.2/anchor.min.js" ></script>
  <script>
    anchors.options = {
      placement: "right",
      visible: "always",
      
    };
    var el = "h1,h2,h3,h4,h5,h6".split(",");
    var res = [];
    for (item of el) {
      res.push(".markdown-body > " + item)
    }
    anchors.add(res.join(", "))
  </script>



  <script  src="/js/local-search.js" ></script>
  <script>
    var path = "/local-search.xml";
    var inputArea = document.querySelector("#local-search-input");
    inputArea.onclick = function () {
      searchFunc(path, 'local-search-input', 'local-search-result');
      this.onclick = null
    }
  </script>



  <script  src="https://cdn.staticfile.org/fancybox/3.5.7/jquery.fancybox.min.js" ></script>
  <link  rel="stylesheet" href="https://cdn.staticfile.org/fancybox/3.5.7/jquery.fancybox.min.css" />

  <script>
    $('#post img:not(.no-zoom img, img[no-zoom]), img[zoom]').each(
      function () {
        var element = document.createElement('a');
        $(element).attr('data-fancybox', 'images');
        $(element).attr('href', $(this).attr('src'));
        $(this).wrap(element);
      }
    );
  </script>







  
  
    <script>
      !function (e, t, a) {
        function r() {
          for (var e = 0; e < s.length; e++) s[e].alpha <= 0 ? (t.body.removeChild(s[e].el), s.splice(e, 1)) : (s[e].y--, s[e].scale += .004, s[e].alpha -= .013, s[e].el.style.cssText = "left:" + s[e].x + "px;top:" + s[e].y + "px;opacity:" + s[e].alpha + ";transform:scale(" + s[e].scale + "," + s[e].scale + ") rotate(45deg);background:" + s[e].color + ";z-index:99999");
          requestAnimationFrame(r)
        }

        function n() {
          var t = "function" == typeof e.onclick && e.onclick;
          e.onclick = function (e) {
            t && t(), o(e)
          }
        }

        function o(e) {
          var a = t.createElement("div");
          a.className = "heart", s.push({
            el: a,
            x: e.clientX - 5,
            y: e.clientY - 5,
            scale: 1,
            alpha: 1,
            color: c()
          }), t.body.appendChild(a)
        }

        function i(e) {
          var a = t.createElement("style");
          a.type = "text/css";
          try {
            a.appendChild(t.createTextNode(e))
          } catch (t) {
            a.styleSheet.cssText = e
          }
          t.getElementsByTagName("head")[0].appendChild(a)
        }

        function c() {
          return "rgb(" + ~~(255 * Math.random()) + "," + ~~(255 * Math.random()) + "," + ~~(255 * Math.random()) + ")"
        }

        var s = [];
        e.requestAnimationFrame = e.requestAnimationFrame || e.webkitRequestAnimationFrame || e.mozRequestAnimationFrame || e.oRequestAnimationFrame || e.msRequestAnimationFrame || function (e) {
          setTimeout(e, 1e3 / 60)
        }, i(".heart{width: 10px;height: 10px;position: fixed;background: #f00;transform: rotate(45deg);-webkit-transform: rotate(45deg);-moz-transform: rotate(45deg);}.heart:after,.heart:before{content: '';width: inherit;height: inherit;background: inherit;border-radius: 50%;-webkit-border-radius: 50%;-moz-border-radius: 50%;position: fixed;}.heart:after{top: -5px;}.heart:before{left: -5px;}"), n(), r()
      }(window, document);
    </script>
  











  

  

  

  

  

  





</body>
</html>
